Self-cleaning filter

ABSTRACT

A self-cleaning filter assembly includes a cylindrical cartridge filter element supported on a coaxially mounted hydrodynamic bearing for rotation of the cartridge filter element about its longitudinal axis. The cylindrical cartridge filter element includes a hollow interior for receiving filtered water. A water spray manifold is provided proximate to the cartridge filter element and includes spray nozzles for providing a water spray capable of rotating the cartridge filter element about its longitudinal axis. A diverter valve receives flow of water to be filtered. With the diverter valve in a first position, the received flow of water submerges the cartridge filter element, with the filtered water received at the hollow interior of the cartridge filter element. With the diverter valve, in a second position, the received flow of water is provided to the water spray manifold causing it to fill under pressure. Water sprays out of the spray nozzles directed at the cartridge filter element causing it to rotate about its longitudinal axis. The water spray cleans the cartridge filter element as it rotates. Additionally, with the diverter valve in its second position, a portion of the water flow to the water spray manifold is tapped off and provided to the hydrodynamic bearing to provide a film of water as the load bearing component allowing rotation of the cartridge filter element thereon.

FIELD OF THE INVENTION

[0001] The present invention is directed toward filters for liquids and,more particularly, toward a self-cleaning water filter for use inswimming pools and the like.

BACKGROUND OF THE INVENTION

[0002] Swimming pools typically use a filtration process to remove dirtand other foreign particles which accumulate in the pool water. The poolwater is pumped by a variety of known means to a filter which removesthe dirt and other solid particles from the pool water. Filtered poolwater is then discharged from the filter directly back to the pool. Inaddition to making the pool water visually appealing, removal of foreignparticles by filtration helps in decreasing the disinfectant demand,typically chlorine, of the pool water necessary for killing diseasecausing bacteria. Typically, five basic types of filter systems areutilized for swimming pools, namely, pressure sand, pressurediatomaceous earth, vacuum diatomaceous earth, gravity sand, andcartridge type filters.

[0003] As the filtration process takes place, filtered particlesaccumulate in the filter adding resistance to, and decreasing the waterflow through, the filter. Typically, once the water flow through thefilter falls below a specified flow rate or pressure, it is recommendedthat the filter be cleaned. With regard to cartridge-type filters, thecartridge filter element is typically removed from the filter housingand rinsed/cleaned with a garden hose to remove the filtered dirt andother solid particles therefrom.

[0004] During normal operation, the water to be filtered typicallyaccumulates in the cartridge filter housing and submerges the filtercartridge. Filtered water collects at an inner volume of the filtercartridge and is drained or pumped back to the pool. Conventional filtercartridges include a plurality of longitudinal pleat folds used forfiltering. Each of these longitudinal pleat folds must be cleaned.Typical filter cartridges take about 20-30 minutes to clean by sprayingwith a garden hose. Cleaning in this manner with a garden hose also hasa disadvantage in that the force of the applied water pushes some of thefiltered debris deeper into the filter medium of the longitudinal pleatfolds, since the build up of filtered debris typically occurs at theouter diameter of the filter cartridge. Experience has shown that theperiodical removing and cleaning of filter cartridges has become a chorethat many pool owners skip. Periodical cleaning of the filter cartridgesis important since a cartridge filter that sits dirty too long, driesand becomes impacted with filtered debris and cannot be cleaned. If thishappens, a new filter cartridge must be purchased.

[0005] The present invention is directed toward overcoming one or moreof the above-identified problems.

SUMMARY OF THE INVENTION

[0006] A self-cleaning filter assembly is provided in accordance withthe present invention. The self-cleaning filter assembly includes acylindrical cartridge filter element supported on a coaxially mountedhydrodynamic bearing for rotation of the cartridge filter element aboutits longitudinal axis. The cylindrical cartridge filter element includesa hollow interior for receiving filtered water. A film of water is usedby the hydrodynamic bearing as the load bearing component enablingrotation of the cartridge filter element. The self-cleaning filterassembly further includes a water spray manifold provided proximate tothe cartridge filter element and having spray nozzles for providing awater spray capable of rotating the cartridge filter element about itslongitudinal axis. In operation, a flow of water to be filtered isreceived by a diverter valve mounted to the filter assembly andpositionable between first and second positions. In the first position,the diverter valve directs the received flow of water to the cartridgefilter element, i.e., submerges the cartridge filter element forfiltering. The filtered water is received at the hollow interior of thecartridge filter element and returned to the pool. In the secondposition, the diverter valve provides the received flow of water to thewater spray manifold causing it to fill under pressure and water spraysout of the spray nozzles directed at the cartridge filter elementcausing it to rotate about its longitudinal axis. The water spray cleansthe cartridge filter element as it rotates. Additionally, with thediverter valve in its second position, a portion of the water flow tothe water spray manifold is tapped off and directed to the hydrodynamicbearing and provides the film of liquid used by the hydrodynamic bearingas the load bearing component.

[0007] A filter housing is also provided completely enclosing thecartridge filter element, hydrodynamic bearing and water spray manifold.The filter housing includes three bi-directional ports formed therein.The self-cleaning filter assembly further includes a discharge plenumalso enclosed by the filter housing. The discharge plenum is in fluidcommunication with the cartridge filter element and includes bottom andside surfaces defining a receptacle for receiving the filtered waterfrom the hollow interior of the cartridge filter element, and an outletport formed in the side surface thereof. The discharge plenum isselectively and removeably attachable to the filter housing to orientits outlet port in fluid communication with any of the three portsformed in the filter housing. Thus, any of the three ports may beutilized as a filter return port for returning filtered water back tothe pool or other source.

[0008] In one form, the discharge plenum is rotatably attached to thefilter housing and selectively rotatable to orient the outlet port influid communication with any of the three ports formed in the filterhousing. The diverter valve is mountable to one of the other two filterports which are not in fluid communication with the outlet port of thedischarge plenum. The remaining filter port is utilized to receive wastewater exterior to the cartridge filter element from the water spraymanifold. Thus, the three filter ports may be interchangeably utilizedas the filter inlet, return and waste ports depending on the desiredfilter configuration.

[0009] The hydrodynamic bearing includes a stationary manifold having aninlet for receiving a pressurized flow of water to be utilized as theload bearing component, a first bearing member received in and attachedto the manifold, and a second bearing member operatively connected tothe first bearing member for rotation with respect to the first bearingmember.

[0010] The first bearing member includes an inner cylindrical wallhaving an axis, an outer cylindrical wall radially spaced from, andcoaxial with, the inner cylindrical wall, a bottom member connectedbetween the inner and outer cylindrical walls, and a first disc memberextending radially outward from the outer cylindrical wall. The firstbearing member is received in and attached to the manifold such that theouter cylindrical wall, the first disc member and the manifold togetherdefine a channel for the received pressurized flow of water at themanifold inlet. A plurality of radial dynamic pressure generatingapertures are formed in the outer cylindrical wall of the first bearingmember and communicate with the channel. Similarly, a plurality of axialdynamic pressure generating apertures are formed in the first discmember of the first bearing member and also communicate with thechannel.

[0011] The second bearing member is designed to support an object, e.g.,a cartridge filter element, for rotation about its axis. The secondbearing member includes a cylindrical portion received between the innerand outer cylindrical walls of the first bearing member, and a seconddisc member extending radially outward from the cylindrical portion andfacing the first disc member with the first and second bearing membersoperatively connected.

[0012] In operation, pressurized water is received by the manifold atits inlet and fills the channel. The pressurized water is providedagainst the cylindrical portion of the second bearing member via theradial dynamic pressure generating apertures in the first bearingmember, and also against the second disc member of the second bearingmember via the axial dynamic pressure generating apertures in the firstbearing member, providing a thin film of water as the load bearingopponent and allowing the second bearing member and the cartridge filterelement supported thereon to rotate about the axis.

[0013] In another form, an inner surface of the outer cylindrical wallof the first bearing member includes a plurality of dynamic pressuregenerating grooves cooperating, one each, with the plurality of radialdynamic pressure generating apertures. In a preferred form, theplurality of dynamic pressure generating grooves extend axially andsubstantially parallel to the axis.

[0014] In a further form, a top surface of the first disc member of thefirst bearing member includes a plurality of dynamic pressure generatingrecessed portions cooperating, one each, with the plurality of axialdynamic pressure generating apertures. Each of plurality of dynamicpressure generating recessed portions preferably includes a bottomsurface and angled side surfaces.

[0015] Preferably, the pluralities of radial and dynamic pressuregenerating apertures, and cooperating grooves and recessed portions,respectively, are equiangularly spaced about the axis.

[0016] In an additional form, the pressurized water is provided to themanifold channel to allow rotation of the second bearing member with thehydrodynamic bearing in an energized state, which corresponds to thesecond position of the diverter valve. The first and second disc memberscooperate to form a seal preventing water from flowing into thehydrodynamic bearing with the hydrodynamic bearing in an unenergizedstate (diverter valve in first position), and permitting a minimalamount of water to flow out of the hydrodynamic bearing through the sealwith the hydrodynamic bearing in the energized state (diverter valve insecond position). Preferably, the seal includes a labyrinth-type sealhaving cooperating teeth formed on facing surfaces of the first andsecond disc members at outer circumferential portions thereof.

[0017] The diverter valve includes a housing mountable to the filterhousing and having an inlet for receiving a flow of water to be filteredand an outlet opening into the filter with the diverter housing mountedthereto. A diverter element is mounted in the diverter housing andextends into the filter through one of the filter ports with thediverter housing mounted thereto. The diverter element is positionablebetween a first position wherein the diverter element directs water atthe diverter housing outlet into the filter housing to submerge thecartridge filter element for normal filtering operation, and a secondposition wherein the diverter element directs water at the diverterhousing outlet to the water spray manifold provided proximate to thecartridge filter element to provide a spray of water capable of rotatingthe cartridge filter element on the hydrodynamic bearing to clean thecartridge filter element. A portion of the water to the water spraymanifold is tapped off and directed to the hydrodynamic bearing for useas the load bearing component.

[0018] An actuation element is attached to the diverter housing and iskeyed to the diverter element for rotation of the diverter elementbetween the first and second position. Preferably, rotation of thediverter element between the first and second position encompasses arotation of 90° in either rotational direction.

[0019] The diverter element includes an elongate body having a hollowcylindrical end portion extending into the filter with the diverterhousing mounted thereto. The cylindrical end portion includes first andsecond openings formed opposite one another. With the diverter elementin the first position (normal filtering), water at the diverter housingoutlet is split and directed through the first and second openings andinto the filter. With the diverter element in the second position(cleaning cycle), one of the first and second openings are blocked offand the other is in fluid communication with the water spray manifold.

[0020] It is an object of the present invention to provide aself-cleaning filter of the cartridge type which allows easy cleaning ofthe cartridge filter element.

[0021] It is a further object of the present invention to provide acartridge type filter which enables the cartridge filter element to becleaned without having to physically remove it from the filter.

[0022] It is yet a further object of the present invention to provide afilter having interchangeable inlet, return and waste ports.

[0023] It is still a further object of the present invention to providea filter of the cartridge type that can be automatically cleaned uponinitiation by a user.

[0024] Other aspects, objects and advantages of the present inventioncan be obtained from a study of the application, the drawings, and theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a cross-sectional view of a self-cleaning filteraccording to the present invention;

[0026]FIG. 2 is an enlarged cross-sectional view of the hydrodynamicbearing, discharge plenum and diverter valve shown in FIG. 1;

[0027]FIG. 3 is a perspective view of the discharge plenum included inthe inventive self-cleaning filter;

[0028]FIG. 4 is a top view of the self-cleaning filter according to thepresent invention illustrating the discharge plenum and the filter portconnections;

[0029]FIG. 5 is an exploded view of the hydrodynamic bearing included inthe inventive self-cleaning filter;

[0030]FIG. 6 is a front view of the manifold included in thehydrodynamic bearing;

[0031]FIG. 7 is a top view of the manifold shown in FIG. 6;

[0032]FIG. 8 is a front view of the first bearing member included in thehydrodynamic bearing;

[0033]FIG. 9 is a top view of the first bearing member shown in FIG. 8;

[0034]FIG. 10 is a cross-sectional view of the first bearing membertaken along line 10-10 in FIG. 9;

[0035]FIG. 11 is a top view of the second bearing member included in thehydrodynamic bearing;

[0036]FIG. 12 is a bottom view of the second bearing member shown inFIG. 11;

[0037]FIG. 13 is a cross-sectional view of the second bearing membertaken along line 13-13 in FIG. 11; and

[0038]FIG. 14 is an exploded view of the diverter valve included in theinventive self-cleaning filter.

DETAILED DESCRIPTION OF THE INVENTION

[0039]FIGS. 1-2 illustrate a self-cleaning water filter, shown generallyat 10, in accordance with the present invention. The water filter 10includes a filter housing 12 having upper 14 and lower 16 filterhousings joined together by a band clamp 18, or other conventionaljoining devices, extending around the full circumference thereof.

[0040] The filter 10 is of the cartridge type and includes a cartridgefilter element 20 in the general shape of a cylinder having a hollowinterior shown at 21. The filter cartridge 20 includes longitudinalpleated folds of filter material 22 supported on a perforated tube 23opening into the hollow interior 21. A bottom end of the filtercartridge 20 is annually supported on a hydrodynamic bearing 24 allowingfree rotation of the filter cartridge 20 about its longitudinal axis 26.A spindle 28 attached to the top center of the upper filter housing 14biases the filter cartridge 20 against the hydrodynamic bearing 24 andallows the filter cartridge 20 to rotate about its longitudinal axis 26.The hydrodynamic bearing 24 is mounted to a discharge plenum 30.

[0041] Referring to FIGS. 1-3, the discharge plenum 30 includes a plenumbody having bottom 32 and side 34 surfaces defining a receptacle 36. Anoutlet port 38 is formed in the side surface 34 and is in fluidcommunication with the receptacle 36. The hydrodynamic bearing 24 ismounted coaxially with the filter cartridge 20 and is in fluidcommunication with the hollow interior 21. Filtered water received atthe hollow interior 21 flows through the hydrodynamic bearing 24, intothe receptacle 36 of the discharge plenum 30, and through the outletport 38 to a filter return port 39 where it is returned to a pool orother water source (not shown).

[0042] Referring to FIGS. 1-2, a diverter valve 40 is mounted to afilter inlet port 41 formed in the filter housing 12 and receives a flowof water to be filtered at its inlet 42. The received water to befiltered flows from the diverter valve outlet 44 and into the interiorof the filter housing 12. The diverter valve 40 is positionable betweena first position for normal filter operation, and a second position forcleaning the filter cartridge 20.

[0043] With the diverter valve 40 in its first position, water flowsthrough the diverter valve 40 and into the filter housing 12substantially submerging the filter cartridge 20. Filtered water flowsinto the hollow interior 21 of the filter cartridge 20, through thehydrodynamic bearing 24 and into the receptacle 36 of the dischargeplenum 30. The filtered water continues through the outlet port 38 ofthe discharge plenum 30 to the filter return port 39, where it isconventionally returned to the pool.

[0044] With the diverter valve 40 in its second position, the flow ofwater to the interior of the filter housing 12 is cut off. The waterreceived by the diverter valve 40 is directed under pressure to a waterspray manifold 46 provided proximate to the filter cartridge 20 andincluding a plurality of spray nozzles 48. The pressurized waterreceived by the water spray manifold 46 sprays out of the spray nozzles48 under pressure and causes the filter cartridge 20 to spin as it isbeing cleaned. The spray nozzles 48 are directed off-center at thefilter cartridge 20 so that the force of the water spray will cause thefilter cartridge 20 to spin about its axis 26. The combination of thecentrifugal force of the spinning filter cartridge 20 and the waterspray from the nozzles 48 clean dirt and other debris from the filtermaterial 22. Waste water sprayed by the manifold 46 and dirt and debrisremoved from the filter cartridge 20 are received in the filter housing12 and discharged through a waste port 49 (see FIG. 3). A portion of thewater provided to the water spray manifold 46 by the diverter valve 40is tapped off and provided to the hydrodynamic bearing 24 for use as theload bearing component allowing the filter cartridge 20 to spin underthe pressure of the water spray from the nozzles 48, as will bedescribed infra.

[0045] As shown more clearly in FIG. 4, the discharge plenum 30 isselectively rotatable such that it may be oriented with various ports inthe filter housing 12 to suit various installations. As shown in FIG. 4,the filter housing 12 includes three ports 39, 41 and 49, with port 39used as a filter return port, port 41 used as a filter inlet port, andport 49 used as a filter waste port. The discharge plenum 30 is attachedto the filter housing 12 via a center retaining screw 50. By looseningand removing the center retaining screw 50, the discharge plenum 30 canbe rotated and its outlet port 38 selectively oriented with any of theports 39, 41 and 49 formed in the filter housing 12. Similarly, thediverter valve 40 may be mounted to any of the filter ports 39, 41 and49, and any filter port may be utilized as the filter waste port. Due tothe selective positioning of the discharge plenum 30, its outlet port 38may be oriented with any of the filter ports 39, 41 and 49, with thediverter valve 40 connected to either of the other two filter ports, andthe remaining filter port used as the filter waste port. Thisflexibility of the discharge plenum 30 permits installation of thefilter 10 to a previously constructed system with a minimum number ofmodifications. It should be understood that the flexibility of thedischarge plenum 30 can also be realized when used with filters havingmore or less than three bi-directional ports.

[0046] As shown in the exploded view of FIG. 5, the hydrodynamic bearing24 includes a stationary manifold 58, a first bearing member 60 and asecond bearing member 62 all coaxially provided along the longitudinalaxis 26. Referring to FIGS. 5-7, the manifold 58 is toroidal in shapeand includes a bottom 64 having a central opening and a sidewall 66extending axially from the bottom 64. A water inlet port 68 is formed inthe manifold side surface 66 for receiving the portion of water tappedoff from the flow of water to the water spray manifold 46 with thediverter valve 40 in its second position. The manifold 58 is attached tothe discharge plenum 30 via screws or other connecting means extendingthrough apertures 70 formed in the manifold bottom surface 64 and intocooperating support members 72 (see FIGS. 3-4) formed in the dischargeplenum 30.

[0047] Referring to FIGS. 5 and 8-10, the first bearing member 60 isreceived in, and attached to, the manifold 58. The first bearing member60 includes an inner cylindrical wall 74 having an axis, an outercylindrical wall 76 radially spaced from and coaxial with the innercylindrical wall 74, and a bottom member 78 connected between the inner74 and outer 76 cylindrical walls. A first disc member 80 extendsradially outward from the outer cylindrical wall 76. The outercylindrical wall 76 further includes a flange 82 extending radiallyoutward at an end opposite the first disc member 80. With thehydrodynamic bearing 24 mounted in the filter 10, the axis of the innercylindrical wall 74 is coaxial with the longitudinal axis 26 of thecartridge filter element 20.

[0048] The first bearing member 60 is received in the manifold 58 withthe first disc member 80 engaging the top circumferential edge of themanifold sidewall 66. Screws or other connecting means extend throughapertures 83 formed in the bottom member 78 and bottom surface 64 toattach the first bearing member 60 to the manifold 58. Attachment inthis manner ensures that both the first bearing member 60 and themanifold 58 are stationary and do not rotate. The flange 82 engages theinner surface of the manifold sidewall 66, such that a circumferentialchannel 84 (see FIGS. 1-2) is formed by the manifold sidewall 66, theouter cylindrical wall 76 and the first disc member 80 for receiving theflow of pressurized water at the manifold inlet 68.

[0049] The outer cylindrical wall 76 includes a plurality of radialdynamic pressure generating apertures 86 formed therein whichcommunicate with the channel 84. The inner surface of the outercylindrical wall 76 includes a plurality of dynamic pressure generatinggrooves 88 cooperating, one each, with the radial dynamic pressuregenerating apertures 86. As shown in FIGS. 5 and 10, the grooves 88extend axially substantially parallel to the axis 26.

[0050] The first disc member 80 includes a plurality of axial dynamicpressure generating apertures 90 formed therein which communicate withthe channel 84. A top surface 91 of the first disc member 80 includes aplurality of dynamic pressure generating recessed portions 92 formedtherein and cooperating, one each, with the axial dynamic pressuregenerating apertures 90. The recessed portions 92 each include asubstantially flat portion 94 cooperating with the axial apertures 90,and radially situated side portions 96 extending from the substantiallyflat portion 94 up to the top surface 91 of the first disc member 80.

[0051] The dynamic pressure generating apertures 86 and 90, andcooperating grooves 88 and recessed portions 92, respectively, areequiangularly spaced about the axis 26 in an alternating arrangement.While eight of each of the apertures 86 and 90, and cooperating grooves88 and recessed portions 92, are shown herein, any number of dynamicpressure generating apertures 86 and 90 and cooperating grooves 88 andrecessed portions 92 may be provided in any spacial arrangement withoutdeparting from the spirit and scope of the present invention.

[0052] Referring to FIGS. 5 and 11-13, the second bearing member 62 isdesigned to support an object, namely the cartridge filter element 20,for rotation about the axis 26. The second bearing member 62 includes acylindrical portion 98 received between the inner 74 and outer 76cylindrical walls of the first bearing member 60, and a second discmember 100 extending radially outward from the cylindrical portion 98and facing the first disc member 80. The second bearing member 62includes an aperture 102 formed therethrough having upper 104 and lower106 portions. The lower aperture portion 106 includes a lip 108 forengaging the inner cylindrical wall 74 of the first bearing member 60,and the upper aperture portion 104 is configured to receive filteredwater from the hollow interior 21 of the filter cartridge 20.

[0053] The top surface 91 of the first disc member 80 and the bottomsurface 109 of the second disc member face each other and includecooperating teeth 110 formed about outer circumferential portionsthereof. With the hydrodynamic bearing 24 assembled, the teeth 110cooperate to form a seal, similar to a labyrinth seal, substantiallypreventing water from flowing into or out of the hydrodynamic bearing24.

[0054] Operation of the inventive filter 10 will now be described. Thecartridge filter element 20 is supported on the top surface 111 of thesecond disc member 100 for rotation about the axis 26. With the divertervalve 40 in its first position (normal filter operation), pool waterreceived at the diverter valve inlet 42 is input to the filter housing12 and substantially submerges the cartridge filter element 20. Thewater flows through the folded pleats of filter material 22, where dirtand other solid particles are removed, and clean filtered water flowsinto the hollow interior 21 through the perforated tube 23. The filteredwater flows through the hydrodynamic bearing 24 and into the receptacle36 of the discharge plenum 30. The filtered water flows through thedischarge plenum outlet port 38 and is output from the filter 10 at thefilter return port 39 where it is conventionally returned to the pool.During normal filter operation, the weight of the saturated filtercartridge 20 pushes down against the first bearing member 62 and closesthe seal formed by the cooperating teeth 110, providing a very difficultpath for water and contaminants to leak back through the hydrodynamicbearing 24 and into the clean filter discharge.

[0055] When the diverter valve 40 is moved to its second position(cleaning position), pool water received at the diverter valve inlet 42is directed to the water spray manifold 46. Just prior to the cleaningcycle being initiated, an air vent 112 and the filter waste port 49 areopened and any water that is in the filter housing 12 that wouldotherwise submerge the filter cartridge 20 and prevent it from spinningis drained away through the filter waste port 49. During the cleaningcycle, pressurized water is provided into the water spray manifold 46and a pressurized spray of water is sprayed out of the spray nozzles 48at an angle that will hydraulically rotate the filter cartridge 20. Thewater spray hits the pleated filter material 22 removing dirt and otherdebris therefrom. The centrifugal force as a result of the filtercartridge 20 spinning also assists in removal of the dirt and otherdebris by forcing it to the outer edges of the filter cartridge 20 whereit can be removed by the water spray. The removed debris and waste wateris collected in the filter housing 12 and output through the filterwaste port 49.

[0056] Rotation of the cartridge filter element 20 about the axis 26 isaccomplished via the hydrodynamic bearing 24. With the diverter valve 40in its second position, a portion of the water to the water spraymanifold 46 is tapped off and supplied to the inlet 68 of the manifold58 by a hose (not shown) connecting the water spray manifold 46 to themanifold inlet 68. This pressurized flow of water enters and fills thechannel 84 providing a uniform pressure distribution throughout theentire manifold 58. The pressurized water in the channel 84 supplies thehydrodynamic bearing 24 with two different and distinct fluid bearingconcepts, namely, a hydraulic thrust and a fluid journal bearing.Pressurized water is provided through the radial dynamic pressuregenerating apertures 86 against the cylindrical portion 98 of the secondbearing member 62. This pressurized water flows through the apertures 86and up the grooves 88 to form a thin film of water providing a journalbearing force against the second bearing member 62. Similarly,pressurized water flows from the channel 84 through the axial dynamicpressure generating apertures 90 and against the bottom surface 109 ofthe second disc member 100. The recessed portions 92 cooperating withthe apertures 90 allow a thin film of water to form between the first 80and second 100 disc members providing a thrust bearing force against thesecond bearing member 62. These journal and thrust bearing forcessupport the load of a saturated filter cartridge 20 and allow the filtercartridge 20 to be rotated about the axis 26. By designing thehydrodynamic bearing 24 in this manner, uniform pressure distribution isestablished throughout the entire channel 84. Further, since water isvirtually an incompressible fluid, hydraulic load calculations can beemployed to size bearing capacities depending on the weight of thesaturated filter cartridge 20. Bearing friction losses are virtuallyeliminated, and bearing noise is virtually non-existent.

[0057] With the hydrodynamic bearing 24 in its energized state, i.e.,the diverter valve 40 in its second position, a small amount of waterwill flow through the tortuous path of the labyrinth seal defined by thecooperating teeth 110. This constant water flow aids in prohibitingcontaminants from leaking back through the seal and into thehydrodynamic bearing 24.

[0058] Referring to FIGS. 1-2 and 14, the diverter valve 40 includes ahousing 113 mountable to the water filter 10 at the filter inlet port41. The housing 113 includes the diverter inlet 42 receiving pool waterto be filtered, and the diverter outlet 44 attached to the filter inletport 41 and directing the pool water to be filtered into the filter 10.A diverter element 114 is mounted in the diverter housing 113 andextends into the water filter 10 with the diverter housing 113 mountedthereto. The diverter element 114 includes an elongate body having ahollow cylindrical end portion 116 extending into the water filter 10with the diverter housing 113 mounted thereto. The hollow cylindricalend portion 116 includes apertures 118 formed on opposite sides, i.e.,180° apart. The other end of the diverter elongate body extends througha housing cap 119 and is keyed to a handle 120. The diverter element 114is positionable between a first position in which the apertures 118 aresubstantially horizontally aligned, and a second position in which theapertures 118 are substantially vertically aligned. Rotation of thediverter element 114, via the handle 120, 90° in either direction willrotate the diverter element 114 between the first and second positions.It should be understood, however, that other angular alignments of theapertures 118 may be implemented to define the first and secondpositions without departing from the spirit and scope of the presentinvention.

[0059] In operation, open tip of the cylindrical end portion 116 isclosed off. Water flows through the diverter valve 40 and into thefilter 10 through the cylindrical end portion 116. With the divertervalve 40/diverter element 114 in the first position, the pool water tobe filtered is split 180° and flows out of the apertures 118 and intothe filter housing 12 where it is filtered in the manner previouslydescribed. Rotation of the diverter element 114, via the handle 120, tothe second position causes one of the apertures 118 to be blocked offand the other aperture 118 to be in fluid communication with the waterspray manifold 46. Thus, water entering the diverter valve 40 isprovided to the water spray manifold 46 for cleaning the filtercartridge 20 in the manner previously described. A hose (not shown) isconnected to the lower portion of the water spray manifold 46 forallowing a portion of the water to be tapped off and supplied to theinlet 68 of the manifold 58 to energize the hydrodynamic bearing 24 forcleaning.

[0060] Since the inventive filter 10 contemplates using the same poolwater that is provided for filtering for cleaning purposes, it isunderstood that a certain amount of pool water will be lost during thecleaning cycle. However, as an example only, adequate cleaning of thefilter cartridge 20 should typically take between 0.75-1.0 minutes, andeven with regular periodic cleaning of the filter cartridge 20 thevolume of water used for cleaning will typically be small compared tothe total volume of water in the pool or other water source beingfiltered. The time for cleaning the filter cartridge will depend onvarious factors, including, but not limited to, the size of the filtercartridge as well as the amount of dirt and other solid particlescollected on the filter cartridge.

[0061] While the present invention has been described with particularreference to the drawings, it should be understood that variousmodifications could be made without departing from the spirit and scopeof the present invention. For example, while the present invention hasbeen described for use in filtering pool water, virtually any type ofliquid may be filtered by the inventive filter 10 without departing fromthe spirit and scope of the present invention. Additionally, the variouscomponents of the inventive filter 10 are fully backward compatible andthe various components of the inventive filter 10 can be sold as aretrofit unit for filters not originally equipped for suchself-cleaning.

I claim:
 1. A hydrodynamic bearing comprising: a stationary manifoldhaving an inlet for receiving a flow of liquid; a first bearing memberreceived in and attached to the manifold, the first bearing membercomprising an inner cylindrical wall having an axis, an outercylindrical wall radially spaced from and coaxial with the innercylindrical wall, a bottom member connected between the inner and outercylindrical walls, and a first disc member extending radially outwardfrom the outer cylindrical wall, wherein the outer cylindrical wall, thefirst disc member and the manifold define a channel for the receivedflow of liquid, wherein the outer cylindrical wall includes a pluralityof radial dynamic pressure generating apertures communicating with thechannel, and wherein the first disc member includes a plurality of axialdynamic pressure generating apertures communicating with the channel;and a second bearing member designed to support an object for rotationabout the axis, the second bearing member comprising a cylindricalportion received between the inner and outer cylindrical walls of thefirst bearing member, and a second disc member extending radiallyoutward from the cylindrical portion and facing the first disc member,wherein pressurized liquid provided against (a) the cylindrical portionvia the radial dynamic pressure generating apertures, and (b) the seconddisc member via the axial dynamic pressure generating apertures, allowsthe second bearing member and an object thereon to rotate about theaxis.
 2. The hydrodynamic bearing of claim 1, wherein the pressurizedliquid is provided to allow rotation of the second bearing member withthe hydrodynamic bearing in an energized state.
 3. The hydrodynamicbearing of claim 2, wherein the first and second disc members cooperateto form a seal preventing liquid from flowing into the hydrodynamicbearing with the hydrodynamic bearing in an unenergized state andpermitting a minimal amount of liquid to flow out of the hydrodynamicbearing with the hydrodynamic bearing in the energized state.
 4. Thehydrodynamic bearing of claim 3, wherein the seal comprises cooperatingteeth formed on facing surfaces of the first and second disc members atouter circumferential portions thereof.
 5. The hydrodynamic bearing ofclaim 1, wherein an inner surface of the outer cylindrical wall of thefirst bearing member includes a plurality of dynamic pressure generatinggrooves cooperating, one each, with the plurality of radial dynamicpressure generating apertures.
 6. The hydrodynamic bearing of claim 5,wherein the plurality of dynamic pressure generating grooves extendaxially substantially parallel to the axis.
 7. The hydrodynamic bearingof claim 1, wherein a top surface of the first disc member includes aplurality of dynamic pressure generating recessed portions cooperating,one each, with the plurality of axial dynamic pressure generatingapertures.
 8. The hydrodynamic bearing of claim 1, wherein the manifoldcomprises a toroidal-shaped manifold.
 9. The hydrodynamic bearing ofclaim 1, wherein the liquid comprises water.
 10. The hydrodynamicbearing of claim 9, employed in a water filter device having acylindrical cartridge filter element supported on the second bearingmember of the hydrodynamic bearing for rotation about the axis.
 11. Thehydrodynamic bearing of claim 10, wherein the hydrodynamic bearingallows the cylindrical cartridge filter element to rotate about the axisvia a water spray from a water spray manifold provided in the waterfilter device.
 12. A hydrodynamic bearing comprising: a stationarymanifold having an inlet for receiving a pressurized flow of liquid; astationary first bearing member attached to the manifold and having astationary shaft member having an axis, the first bearing member andmanifold defining a channel for the received pressurized flow of liquid,wherein the first bearing member includes pluralities of radial andaxial dynamic pressure generating apertures in communication with thechannel; and a second bearing member received on the stationary shaftmember and rotatable about the axis, the second bearing memberconfigured to support an object for rotation about the axis, whereinpressurized liquid is provided against the second bearing member via theradial and axial dynamic pressure generating apertures in the firstbearing member providing journal bearing and thrust bearing forces,respectively, against the second bearing member allowing the secondbearing member and an object thereon to rotate about the axis.
 13. Thehydrodynamic bearing of claim 12, wherein the liquid comprises water.14. The hydrodynamic bearing of claim 12, wherein the first bearingmember includes a plurality of dynamic pressure generating groovesradially facing the second bearing member and cooperating, one each,with the plurality of radial dynamic pressure generating apertures. 15.The hydrodynamic bearing of claim 14, wherein the pluralities of dynamicpressure generating grooves and apertures are equiangularly spaced aboutthe axis.
 16. The hydrodynamic bearing of claim 12, wherein the firstbearing member includes a plurality of dynamic pressure generatingrecessed portions axially facing the second bearing member andcooperating, one each, with the plurality of axial dynamic pressuregenerating apertures.
 17. The hydrodynamic bearing of claim 16, whereinthe pluralities of dynamic pressure generating recessed portions andapertures are equiangularly spaced about the axis.
 18. The hydrodynamicbearing of claim 12, wherein the pressurized liquid is provided to allowrotation of the second bearing member with the hydrodynamic bearing inan energized state.
 19. The hydrodynamic bearing of claim 18, whereinthe first and second bearing members include first and second discmembers, respectively, facing each other and cooperating to form a sealpreventing liquid from flowing into the hydrodynamic bearing with thehydrodynamic bearing in an unenergized state and permitting a minimalamount of liquid to flow out of the hydrodynamic bearing with thehydrodynamic bearing in the energized state.
 20. The hydrodynamicbearing of claim 19, wherein the seal comprises cooperating teeth formedon facing surfaces of the first and second disc members at outercircumferential portions thereof.
 21. A diverter valve for use with awater filter having a cartridge filter element supported on ahydrodynamic bearing for rotation thereon, the hydrodynamic bearingusing a film of water as the load bearing component, the diverter valvecomprising: a housing mountable to the water filter, the housing havingan inlet for receiving a flow of water to be filtered and an outletopening into the water filter with the housing mounted thereto; and adiverter element mounted in the housing and extending into the waterfilter with the housing mounted thereto, the diverter elementpositionable between a first position wherein the diverter elementdirects water at the housing outlet into the water filter for normalfiltering operation, and a second position wherein the diverter elementdirects water at the housing outlet to a water spray manifold providedproximate to the cartridge filter element, the water spray manifoldhaving spray nozzles for providing a water spray capable of rotating thecartridge filter element on the hydrodynamic bearing, wherein a portionof the water flow to the water spray manifold is tapped off and directedto the hydrodynamic bearing to provide the film of water as the loadbearing component.
 22. The diverter valve of claim 21, furthercomprising an actuation element connected to the diverter element forrotation of the diverter element between the first and second positions.23. The diverter valve of claim 22, wherein the diverter elementincludes an elongate body having a hollow cylindrical end portionextending into the water filter with the housing mounted thereto, thecylindrical end portion having first and second openings formed oppositeone another, wherein with the diverter element in the first positionwater at the housing outlet is directed through the first and secondopenings and into the water filter, and with the diverter element in thesecond position one of the first and second openings is blocked off andthe other is in fluid communication with the water spray manifold. 24.The diverter valve of claim 22, wherein rotation of the diverter elementbetween the first and second positions includes rotation of the diverterelement 90° in either rotational direction.
 25. The diverter valve ofclaim 22, wherein the actuation element includes a handle for manualrotation of the diverter element between the first and second positions.26. A diverter valve comprising: a housing having an inlet for receivinga flow of liquid, and an outlet; a diverter element mounted in thehousing and extending from the housing outlet, the diverter elementincluding an elongate body having a hollow cylindrical end portionextending from the housing outlet and having at least one opening formedtherein, wherein liquid received at the housing inlet passes through thehousing outlet and out the at least one opening in the cylindrical endportion; and an actuation element connected to the diverter element forrotation of the diverter element between a plurality of rotationalpositions.
 27. The diverter valve of claim 26, wherein the at least oneopening includes first and second openings formed opposite one another,wherein liquid received at the housing inlet passes through the housingoutlet and is split in 180° opposed directions through the first andsecond openings.
 28. The diverter valve of claim 26, wherein theactuation element includes a handle for manual rotation of the diverterelement between the plurality of rotational positions.
 29. The divertervalve of claim 26, wherein the liquid comprises water and the housing ismountable to a water filter such that the hollow cylindrical end portionof the diverter element extends into the water filter with the housingmounted thereto, wherein with the diverter element in a first positionwater at the housing outlet is directed through the at least one openingand into the water filter for normal filtering operation, and whereinwith the diverter element in a second position water at the housingoutlet is directed through the at least one opening to a water spraymanifold provided proximate to a cartridge filter element used fornormal filter operation, the water spray manifold having spray nozzlesfor providing a water spray to the cartridge filter element for cleaningthe cartridge filter element.
 30. The diverter valve of claim 29,wherein the cartridge filter element is supported on a hydrodynamicbearing for select rotation thereon, the hydrodynamic bearing using afilm of water as the load bearing component to allow rotation of thecartridge filter element, wherein a portion of the water flow to thewater spray manifold is tapped off and directed to the hydrodynamicbearing to provide the thin film of water as the load bearing component,and wherein the water spray manifold spray nozzles provide a water spraycapable of rotating the cartridge filter element on the hydrodynamicbearing for cleaning the cartridge filter element.
 31. A dischargeplenum for use in a filter having a filter housing with at least twoports and a filter element for filtering a liquid received in the filterhousing, the discharge plenum comprising: a plenum body having bottomand side surfaces defining a receptacle for receiving a flow of filteredliquid filtered by the filter element; and an outlet port formed in theside surface, wherein the plenum body is selectively and removablyattachable to the filter housing to orient the outlet port in fluidcommunication with any of the at least two ports formed in the filterhousing.
 32. The discharge plenum of claim 31, wherein the plenum bodyis rotatably attached to the filter housing and selectively rotatable toorient the outlet port in fluid communication with any of the at leasttwo ports formed in the filter housing.
 33. The discharge plenum ofclaim 31, wherein the liquid to be filtered is received by the filterhousing at one of the at least two ports not in fluid communication withthe outlet port of the discharge plenum.
 34. The discharge plenum ofclaim 31, wherein the liquid comprises water.
 35. A self-cleaning filterassembly for liquids comprising: a cylindrical cartridge filter elementhaving a hollow interior for receiving filtered liquid, the cartridgefilter element having a longitudinal axis; a hydrodynamic bearingproviding support for, and mounted coaxially with, the cartridge filterelement, the hydrodynamic bearing using a film of liquid as the loadbearing component such that the cartridge filter element is able torotate about its longitudinal axis; a liquid spray manifold providedproximate to the cartridge filter element and having spray nozzles forproviding a liquid spray capable of rotating the cartridge filterelement about its longitudinal axis on the hydrodynamic bearing; and adiverter valve receiving a flow of liquid to be filtered, the divertervalve positionable between a first position wherein the received flow ofliquid is provided to the cartridge filter element for filtering, and asecond position wherein the received flow of liquid is provided to theliquid spray manifold, wherein a portion of the liquid flow to theliquid spray manifold is tapped off and provided to the hydrodynamicbearing to provide the film of liquid as the load bearing component. 36.The self-cleaning filter assembly of claim 35, further comprising: afilter housing completely enclosing the cartridge filter element,hydrodynamic bearing and liquid spray manifold, and to which thediverter valve is mounted, wherein with the diverter valve in the firstposition the received flow of liquid is directed into the filter housingto submerge the cartridge filter element.
 37. The self-cleaning filterassembly of claim 35, further comprising: a filter housing completelyenclosing the cartridge filter element, hydrodynamic bearing and liquidspray manifold, the filter housing having first, second and third ports;and a discharge plenum enclosed by the filter housing, the dischargeplenum having bottom and side surfaces defining a receptacle forreceiving the filtered liquid from the hollow interior of the cartridgefilter element and an outlet port formed in the side surface, whereinthe discharge plenum is selectively and removably attachable to thefilter housing to orient the outlet port in fluid communication with anyof the first, second and third ports formed in the filter housing. 38.The self-cleaning filter assembly of claim 37, wherein the dischargeplenum is rotatably attached to the filter housing and selectivelyrotatable to orient the outlet port in fluid communication with any ofthe first, second and third ports formed in the filter housing, whereinthe diverter valve is mounted to one of the first, second and thirdports not in fluid communication with the outlet port of the dischargeplenum, and wherein a remaining port of the first, second and thirdports receives a flow of liquid exterior to the cartridge filter elementfrom the liquid spray manifold.
 39. The self-cleaning filter assembly ofclaim 35, wherein the liquid comprises water.